Green and Black Tea Phenolics: Bioavailability, Transformation by Colonic Microbiota, and Modulation of Colonic Microbiota

J Agric Food Chem. 2018 Aug 15;66(32):8469-8477. doi: 10.1021/acs.jafc.8b02233. Epub 2018 Jul 31.


Monomeric green tea catechin (GTC) and oligomeric, oxidized black tea phenolic (BTP) have shown promising health benefits, although GTC has been more extensively studied than BTP. We review the current knowledge on bioavailability, colonic transformation, and gut microbiota modulatory effects of GTC and BTP. As a result of their similar poor bioavailability in the small intestine and potentially similar metabolites upon colonic fermentation, it seems as if GTC and BTP have similar health effects, although it cannot be excluded that they have different gut microbiota modulatory effects and that BTP gives a poorer yield of bioactive phenolic metabolites upon colonic fermentation than GTC.

Keywords: bioavailability; black tea phenolics; green tea catechins; gut microbiota; health benefits; microbial metabolism.

Publication types

  • Review

MeSH terms

  • Animals
  • Bacteria / metabolism*
  • Biotransformation
  • Camellia sinensis / chemistry
  • Camellia sinensis / metabolism*
  • Colon / metabolism
  • Colon / microbiology*
  • Gastrointestinal Microbiome*
  • Humans
  • Phenols / analysis
  • Phenols / metabolism*
  • Plant Extracts / analysis
  • Plant Extracts / metabolism*


  • Phenols
  • Plant Extracts